I think it's alpha but α is annoying to write (outside Greece at least).
But yeah, grouping people in generations isn't really explaining much beyond "people of different ages view this new situation differently". I think it's a very American thing. We don't care as much about generations in Europe and hardly ever name them.
In the case of this post, I'd say it's more a fact that the early seasons of The Simpsons are 20-30 years old rather than different generations have different perspectives. Gen alpha will not be exposed to those seasons unless it's by someone older.